Variable point distributor



Jan. 27, 1942. A. s. H. VANDERPOEL ETAL 2,270,982

VARIABLE POINT DISTRIBUTOR Filed March 5, 1940 3 Sheets-Sheet l Jan. 27;1942. A. G. H. VANDERPOEL ETAL 2,270,932

VARIABLE POINT DISTRIBUTOR Filed March 5, 1940 3 Sheets-Sheet 2 7fizz/6716 0713: 3 QZZerZGHVnciegvoeZ 2101272501777, OSZZZL Q Jan; 27,1942. A. e. H. VANDERPOEL ETAL 2,270,932

VARIABLE POINT DISTRIBUTOR Filed March 5, 1940 3 Sheets-Sheet 3fizverzznsr Patented Jan. 27, 1942 VARIABLE POINT DISTRIBUTOR Albert G.H. Vanderp oel and William Ostling,

Lo Angeles, Calif., assignors to California. Machinery & Supply 00.,Ltd., Los Angelcs, Calif., a corporation of Delaware Application March5, 1940, Serial No. 322,314

7 Claims.

vance of the circuit breaker and varying thev periods of closed circuitfor the primary coil of ignition circuits for internal combustionengines. The present invention is particularly applicable to enginescontaining a relatively large number of cylinders, such, for example, asaeroplane and automobile engines having more than eight cylinders.

The present invention utilizes a circuit breaker of the type having twobreaker arms cooperating with a single cam. In such a device, a twelvecylinder engine requires a cam, the angle between the points of which isonly thirty degrees. It is readily apparent that at high speeds, inorder to maintain the primary circuit closed for a suflicient length oftime to adequately charge the core of the ignition coil, it is necessaryto use a relatively large amount of the thirty degrees for the closedcircuit period. Yet at idling speed, it is desirable to utilize only asmall amount of the thirty degrees for charging the core and thus avoidover saturation.

In accordance with the present invention, we

propose to utilize two breaker arms, the cam engaging heels of which areset to maintain the circuit open for substantially the maximum allowableportion of the time between successive closings when the engine is idle.The breaker arms are controlled by the flow of air and fuel in theintake conduit to increase the closed circuit time and decrease the opencircuit time as the velocity of the air and fuel mixture increases. Oneof these breaker arms is so connected as to respond to increase in theair and fuel velocity in the intake of the engine and thus advance withrespect to the cam. The other breaker arm is so connected as to not beresponsive to the increase in velocity of the air and fuel mixture untilafter the first breaker arm has been advanced a predetermined amount.Thereafter, the two breaker arms are both moved for advancing the spark,but one is moved more than the other so as to vary the proportionalperiods of open and closed circuit while the spark is advanced.

By virtue of advancing one breaker arm independently of the other, Wecreate a varying period of overlap between the action of the cam on thebreaker arms so that the breaker contact points, as the engine speedsup, can remain closed for a greater portion of the angle through whichthe cam travels between successive breaks in the circuit. For example,in a twelve cylinder engine, this action may be continued up to acertain maximum amount of overlap which enables the cam to travel asmuch as twenty-five degrees with the points closed. Preferably, thiscondition is reached at full load. Utilizing a suction control similarto that illustrated in our'prior application Serial No. 306,606, filedNovember 29, 1939, we obtain further advance of both breaker arms andthereby obtain substantial advance of the spark for engine operation athigh speed. The relative positions of the breaker arms for the furtherspark advance continues to change as one arm advances faster than theother. Therefore, the periods of open and closed circuit for the primarycoil will continue to change. The present invention contemplates alsocertain improvements in connecting and mounting the breaker arms movablyabout the cam in order that a more effective control from the velocityof air and fuel in the intake conduit may be accomplished.

Other features and advantages of the present invention will appear morefully as the description proceeds, reference being had to theaccompanying drawings, wherein a preferred embodiment of the inventionis shown. It is to be understood, however, that the drawings anddescription are illustrative only, and are not to be taken as limitingthe invention except insofar as it is limited by the claims.

In the drawings, I

Fig. l is an assembly view partly in section showing the connections ofthe distributor to the air and fuel intake for an internal combustionengine;

Fig. 2 is a plan view of the cam and breaker arm construction of thedistributor;

Fig. 3 is a sectional view taken substantially on the line 33 of Fig. 2;

Fig. 4 is an enlarged fragmentary detail view taken on the line 4-4 ofFig. 2;

Fig. 5 is a fragmentary plan view similar to Fig. 2 showing the changedposition of the parts;

Fig. 6 is a fragmentary sectional view taken on a the line 6-6 of Fig.2;

trating a modified iorm of suction inlet to the air intake conduit ofthe engine, and

Fig. 12 is a diagrammatic view illustrating he relative angularpositions of the breaker arm heels in the two limiting positions ofadjustment.

Referring now in detail to the drawings, the present invention isembodied in a circuit breaking mechanism for spark distributors whereinthe primary circuit of the distributor is opened and closed by means ofa cam cooperating with certain contact carrying breaker arms. Thepresent device comprises a distributor H2, a suction operated diaphragmconnected to a spark advancing link l2 and pressed toward the link l2 bya spring I3. The diaphragm II and the spring |3 are contained in asuitable housing 14, the interior of which is connected by a conduit l5to an air and fuel intake conduit Hi. The conduit I6 includes a Venturithroat I! and a portion I8 which connects to the intake manifold of theengine. The usual throttle valve |9 is provided in the conduit [6. Thesuction conduit I5, as shown in Fig. 1, opens into the Venturi throat Hat 2|] and has an additional check valve controlled opening 2| into theconduit l6 just above the throttle valve I9. The position of the inlet2| is such that when the valve is slightly open the inlet will be on thelower side of the throttle valve. However, when the valve is closed, itwill pass beyond the inlet 2|, thus placing the inlet on the upstreamside of the valve. A check valve 22 is backed up by a spring 23 so that,except when the suction at the inlet 2| is in excess of the suction atthe inlet 20, the

inlet 2| is cut off from the conduit l5. In normal full load conditions,with the throttle valve |9 wide open, it will be understood that thegreater suction will be applied at the inlet 20, but when the throttlevalve is in partially closed position, as, for example, in the positionshown in Fig. 1, the velocity of the air past the throttle valve andpast the inlet 2| will create more suction in the inlet 2| than at theinlet 20.

Referring now particularly to Figs. 2-l0 inclusive, we will describe themechanism whereby the suction in the air intake conduit I5 is utilizedto control the advance of the opening of the primary circuit of theignition coil with respect to the engine driven cam which actuates thecircuit breaker of the spark distributor. As shown best by Figs. 2 and3, the spark distributor embodies a cup-shaped base 24 which is mountedon a supporting member 25. The base 24 includes an insert 26 in which abearing 2! is provided for the cam shaft 28. The details of the camshaft support are of no particular importance to the present inventionand will not be described in detail. The cam shaft 28 carries at itsupper end the usual cam 29 which is provided with the same number ofpoints as there are cylinders in the engine, that is, for a twelvecylinder engine there would be twelve points, while for a nine cylinderengine there would be nine points. Two circuit breaker arms 30 and 3|are disposed on opposite sides of the cam 29. The breaker arm 30 has aheel 32 riding on the cam 29. The breaker arm 3| has a heel 33 riding onthe cam 29.

The breaker arm 30 carries a contact 34 which is adapted to cooperatewith a relatively stationary contact 35 to close one point in theprimary circuit of the ignition coil. Similarly, the breaker arm 3|carries a contact 36 which cooperates with a relatively stationarycontact 31 to close another point in the primary circuit.

A mounting plate 38 is provided with a pin 39 upon which the breaker armis pivotally mounted. An insulating bushing 40 supports the breaker armon the pin 39 and insulates it from the plate 38 so that electricalconnection to the plate 38 from the arm 30 must be through con tacts 34and 35. A spring 4| is fixed to the arm 30 and serves to urge the heel32 of the arm against the cam 2.9. The spring 4| is supported from theplate 38 by means of a bar 42 of insulating material which is riveted toan upstanding flange 43 on the plate 38. The stationary contact 35 isadjustably mounted on an upstanding flange 44 of the plate 38.Electrical connection is made to the breaker arm 30 through a terminal45 on the spring 4|,

The breaker arm 3| is supported on a pin 46 mounted on a plate 4'! whichis similar in all respects to the plate 33. An insulating bushing 48insulates the arm 3| from the plate 41. The plate 41 supports a spring49 and the connecting mechanism for the spring 49, as well as the meansfor supporting the contact 31, are the same on the plate 41 as they areon the plate 38. A terminal 50 is provided on the spring 49 forconnection to the ignition coil circuit.

The plate 38 is mounted upon a supporting plate 5| which, in turn, issupported by a hub 52 (see Figs. 3 and 9) that is journalled on areduced portion 53 of the cam shaft 28, The reduced portion of the camshaft has a collar 54 on top of the bearing 21. A ball bearing race 55rests on the collar 54 and supports the hub 52 for rotative movementabout the reduced part 53 of the shaft 23. The plate 41 is supportedupon a mounting plate 56 (see Figs. 3 and 8) which, in turn, is carriedby a hub 51. The hub 51 is rotatably journalled on the reduced portion53 by a ball bearing race 58. A collar 59 separates the bearings 55 and58 and another collar 6|) separates the bearing 58 with respect to thecam 29.

By means of the construction just described, the two breaker arms 30 and3| are rotatably journalled on the reduced extension 53 so that they maybe turned to advance them with respect to the cam 29 and thus controlthe advance of the primary circuit breaker for the distributor inaccordance with the movements of the diaphragm The arrangement is suchthat the breaker arm 30 is advanced in response to the initial movementof the link |2 as suction increases in the intake conduit l6 from thecondition existing at idling speed of the engine. On the other hand, thebreaker arm 3| is not advanced initially, but is only advanced after apredetermined advance of the breaker arm 30.

The link |2 is connected directly to the plate 5| by means of a pivotscrew 5|. The plate 56 is connected to the plate 5| through 'a lostmotion connection comprising a link 52 connected by a pin 63 and slot 64to the plate 5|. The link 82 connects to a lever 55 by means of a pivotpin 66. The lever 65 (see Fig. 6) is pivoted on the insert 26 by meansof a screw 61. A link 68 connects the free end of the lever 65 to theplate '55, pins 59 and 10 providing pivots for this connection.

The plate 56 is normally held in the position shown in Fig. 2 by meansof a stop pin 1| mounted in the cup 24 and a projection 12 on the plate56. A spring 13 under tension between a pin 14 on the plate 56 and a pin15 on the cup 24 holds the projection '12 against the stop 1|, When theplate 5| is moved in a clockwise direction, it initially does not affectthe position of plate 55. However, as soon as the lost motion affordedby the pin and slot connection at 63 and 64 is taken up, the furthermovement of the plate will also move the plate 56 in a clockwisedirection against the tension of the spring 13. During the movement ofboth plates 5| and 56, there will be a change in the relative positionsof the breaker arm heels 32 and 33- due to the fact that the pivot screw61 is closer to one end of the lever 65. The relation as shown is'suchthat the end of lever 65 to which the link 68 is connected is aboutone-half as far from the pivot of the lever as the end to which the link62 is connected. There will also be a change in the angularposition ofboth breaker arms with respect to the cam 29. Since the angular movementof the plates 5| and 56 is in the opposite direction to the direction ofrotation of the cam 29, their movement results in an advance of theopening of the primary circuit of the ignition coil. In other words, thespark is advanced while changing the relative periods of open circuitand closed circuit when the two plates 5| and '56 are advanced together.

The modified form of suction inlet to the air and fuel intakeillustrated in Fig. 11 utilizes a suction conduit l5, but utilizes onlyone inlet ?6 to the intake conduit. This inlet includes an elongatedslot 1'! formed in the inner wall of the intake conduit and extendingupstream from substantially the closed position of the throttle valve.The purpose of the inlet 76 and the elongated slot 71 is the same as thepurpose I of the two inlets in the main form of the in- 35 vention. Theelongated slot is a simpler construction, however, and produces agradual increase in suction in the conduit l5 as the throttie valve ismoved toward closed position. Under light load and high speed, thisdevice will give the proper amount of suction to advance the spark in avery simple and effective manner.

Referring now to the preferred form of the invention, and particularlyto Figs. 1, 2 and 12, the operation will be briefly described. The lostmotion provided at 64 is for certain engines requiring very littleflywheel advance. It is desirable to avoid too long a dwell which wouldkeep the primary circuit closed and cause oversaturation of the core ofthe ignition coil. Therefore, at low speed, the contacts closing thecircuit through the primary of the ignition coil should be keptseparated through the major part of the cycle of energizing anddeenergizing the ignition coil. The breaker arms and 3| are accordinglyset so that, when the engine is running at low speed, their normalposition is such that the heels of the breaker arms 30 and 3| areengaged by the cam at substantially the same instant, and the contacts34 and are opened at the same time as the contacts 36 and 31. As theheel 32 of the breaker arm 30 rides over the adjacent cam point, and thecontacts 34 and 35 approach each other, the heel 33 on the breaker arm3| also rides over the adjacent cam point, and the contacts 38 and 3'!close when the contacts 34 and 35 come together. The circuit of theprimary coil is thus held open during the entire time necessary for theheels 32 and 33 to pass over the corresponding points of the cam untilthe contacts 34 and 35 and the contacts 36 and 37 come together.

The operation just described enables us to obtain a relatively longperiod of open circuit for the primary coil when the engine is idling.

A correspondingly short period exists for saturating the core of theignition coil. Over-saturation is thus avoided and the resultant heatingand burning of points is eliminated.

As the engine speeds up, the increased velocity of air intake conduitcreates a vacuum in the housing |4 so that the diaphragm moves againstthe spring |3, causing the link |2 to move to the left, as shown in Fig.2. The link l2 causes the plate 5| to rotate in a clockwise direction.This advances the position of the breaker arm 30 with respect to the cam29, but at first has no effect upon the position of the breaker arm 3|because of the lost motion at 64.

As a result of advancing the breaker arm 30, its contacts 34 and 35 openbefore the contacts 36 and 31 open. The circuit of the primary coil isnot opened, however, until both sets of contacts open. However, it isagain closed as soon as the contacts 34 and 35 close. The net result ofthe advance of the breaker arm 3|) independently of the breaker arm 3|is to reduce the period of open circuit, as measured in degrees ofrotation of the cam, causing the period that the breaker arm 30 holdsits contacts open to overlap less with the period that the breaker arm3| holds its contacts open.

The proportion of each cycle during which the primary circuit of theignition coil is held open is, therefore, greatest at idling speed andis reduced as the breaker arm 30 is advanced. The proportion of closedcircuit of the primary coil is increased and the proportion of opencircuit thereof is decreased as the breaker arm 30 is advanced as far asit can without also advancing the breaker arm 3|. This lost motion at 64is necessary with certain engines to obtain full coil saturation as thespeed is increased.

The advance of the spark plug will begin as soon as the breaker arm 30has advanced far enough to also cause the breaker arm 3| to advance. Theadvance is increased by the higher suction obtained in the conduit l5and the housing it when the throttle valve i9 is partly closed, as shownin Fig. 1. The further advance continues to effect a change in theproportion of times of open and closed circuit for the primary coilbecause the two breaker arms 30 and 3|, although advanced together, areadvanced dififerent amounts. That is, the arm 30 is advanced furtherbecause of the greater length of lever arm 65 connected to it.

The two sets of contacts 34-45 and 38-37 control parallel points in theprimary circuit of the ignition coil, as will be readily understood. Thecycle of operation of the ignition controlling device is as follows:Assuming that the engine is idling, the breaker arms 30 and 3| are inthe full line position shown in Fig. 12. Both contact pairs willtherefore open during the same travel of the cam is. The opening of thethrottle and the speeding up of the engine will first advance the arm 3As the arm 30 advances independently of the arm there will be ashortening of the angular travel of the cam during which both contactpairs are open. The shortening wili continue until the limit of movementof the arm allowed by the slot 64 is reached. The dotted line showing ofthe arm 30 in Fig. 12 represents this position. This limit of movementmay be made more or less in any particular de vice by changing thelength of the slot 64 in the plate Hi.

When the suction in the conduit I5 is further increased, the two breakerarms 3|] and 3| are both advanced together, but the arm 30 is advancedfurther than the arm 3 1. Thus the spark is advanced and there is afurther gradual increase in the proportionate time in the cycle du inswhich the primary coil circuit is closed.

From the foregoing description it is believed that the nature of thepresent invention will be readily apparent to those skilled in this art.Having thus described our invention, what we claim as new and desire tosecure by Letters Patent is:

1. A timing apparatus for internal combustion engines having means foradjusting the timing apparatus for differential operation as the1novement of the air and fuel mixture through the air intake varies, thecombination of a cam, two breaker arms movably mounted adjacent to saidcam so as to be operable thereby, separate supporting members for saidbreaker arms respectively adapted to have rotary movement about the camindependently of each other, contact members adjacent to said cam, othercontact members mounted on said breaker arms respectively so as to bemovable into and out of engagement with said first-named contact memhersfor producing sparks in timed relation as said breaker arms are actuatedby said cam, actuating means for giving one of said breaker arms amovement about said cam so as to vary the effect of the cam thereon, andlost motion connections between said actuating means and the otherbreaker arm for giving said other breaker arm a delayed movement in thesame direction about said cam.

2. A timing apparatus for internal combustion engines having means foradjusting the timing apparatus {or differential operation as themovement of the air and fuel mixture through the air intake varies, thecombination of a cam, two breaker arms movably mounted adjacent to saidcam so as to be operable thereby, separate supporting members for saidbreaker arms respectively adapted to have rotary movement about the camindependently of each other, contact members adjacent to said cam, othercontact members mounted on said breaker arms respectively so as to bemovable into and out of engagement with said first-named contact membersfor producing sparks in timed relation as said breaker arms are actuatedby said cam actuating means for giving one of said breaker arms amovement about said cam so as to vary the effect of the cam thereon,yielding means normally holding said other breaker arm yieldinglyagainst movement in the same direction about said cam, and lost motionconnections between said actuating means and said other breaker armadapted to give said other breaker arm a delayed movement against theaction of said yielding means after said one breaker arm has passedthrough the initial portion of its adjustment movement.

3. A timing apparatus for internal combustion engines having means foradjusting the timing apparatus for diiierential operation as themovement of the air and fuel mixture through the air intake varies, thecombination of a cam, two breaker arms movably mounted adjacent to saidcam so as to be operable thereby, separate supporting members for saidbreaker arms respectively adapted to have rotary movement about the camindependently of each other, contact members adjacent to said cam, othercontact members mounted on said breaker arms respectively so as to bemovable into and out of engagement with said first-named contact membersfor producing sparks in timed relation as said breaker arms are actuatedby said cam, actuating means for giving the supporting member for one ofsaid breaker arms a movement about said cam so as to vary the effect ofthe cam on said breaker arm, and lost motion connections between saidsupporting members for giving the supporting member for the other one ofsaid breaker arms a delayed movement in the same direction about saidcam.

i. A timing apparatus for internal combustion engines having means foradjusting the timing apparatus for differential operation as themovement of the air and fuel mixture through the air intake varies, thecombination of a cam, two breaker arms movably mounted adjacent to saidcam so as to be operable thereby, separate supporting members for saidbreaker arms respectively adapted to have rotary movement about the camindependently of each other, contact members adjacent to said cam, othercontact members mounted on said breaker arms respectively so as to bemovable into and out of engagement with said first-named contact memborefor producing sparks in timed relation as said breaker arms are actuatedby said cam, and actuating means operatively connected with said breakerarms adapted by an operative movement to give one of said breaker arms amovement about said cam at one rate and to give other of said breakerarms a movement about the cam at a slower rate.

5. A timing apparatus for internal combustion engines having means foradjusting the timing apparatus for diiierential operation as themovement of the air and fuel mixture through the air intake varies, thecombination of two sets of cooperating contacts adapted when connectedin parallel with each other in a circuit to break the 'circuit forproducing a spark only when both sets or contacts are opensimultaneously, and means acting on both sets of contacts adapted in oneadjustment to hold both sets open for the same time and adjustable so asto change the time of opening one set in comparison with the time ofopening the other set whereby the period during which the circuit isbroken may be controlled.

6. A timing apparatus for internal combustion engines having means foradjusting the timing apparatus for differential operation as themovement of the air and fuel mixture through the air intake varies, thecombination of two sets of cooperating contacts adapted when connectedin parallel with each other in a circuit to break the circuit forproducing a spark only when both sets of contacts are opensimultaneously, means acting on both sets of contacts adapted normallyto open and close both sets substantially simultaneously and adjustablefor changing the time or action on said two sets or contacts, andactuating means adapted by the initial portion of a stroke in onedirection to adjust said contact opening means for advancing the actionon one set of contacts while leaving the action on the other set ofcontacts unchanged so as to cut down the period during which the circuitis broken and adapted by a later portion of said stroke to adjust saidcontact opening means for advancing still further the action on said oneset of contacts and for advancing to a smaller extent the action on saidother set of contacts.

7. A timing apparatus for internal combustion engines having means foradjusting the timing tively so as to be movable into and out ofengagement with said first-named contact members for producing sparks intimed relation as said breaker arms are actuated by said cam, a linkpivotally connected with one of said supporting members for giving it amovement about said cam so as to vary the effect of the cam on thebreaker arm carried by said supporting member, and connections betweensaid two supporting members comprising a lever pivotally mounted on avertical axis adjacent to said supporting members, a link providing alost motion connection between said lever and said one supportingmember, and a second link connecting the other of said supportingmembers with said lever at a point substantially closer to the pivotalaxis of the lever than that at which the other link is connected to saidlever.

ALBERT G. H. VANDERPOEL.

WILLIAM OSTLING.

